The invention relates to a piston-cylinder unit, in particular gas spring, having a cylindrical pressure tube which has a surface protection on its outer side, and having a piston, which is axially displaceable within the pressure tube and has a piston rod, the piston rod being led out of the pressure tube in a sealed manner through an end side opening at a piston-rod-exit end side of the pressure tube. The invention also relates to a process for producing a piston-cylinder unit, in particular a gas spring, having a cylindrical pressure tube and having a piston which is axially displaceable in the pressure tube and has a piston rod, the piston rod being led out of the pressure tube in a sealed manner at a piston-rod-exit end side of the pressure tube.
A piston-cylinder unit as described above and a process as described above are known in the context of a piston-cylinder unit whereof the pressure tube is provided with a shrink-fit hose consisting, for example, of a plastic as surface protection. The shrink-fit hose can if appropriate be adhesively bonded to the surface of the pressure tube which is covered by the shrink-fit hose by means of an adhesive. It is also possible for the shrink-fit hose to surround part of the piston-rod-exit end face of the pressure tube. With the surface protection which comprises a shrink-fit hose, it is relatively difficult to avoid possible fluctuations in the corrosion prevention properties of the surface protection.